• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.38-46
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• 1996

The purpose of this study is to develop the miniaturized duplexer filter for mobile communications using high dielectric constant (${\varepsilon}$r > 100, 180) ceramic resonators. Duplexer filter was ocmposed of ceramic resonators which has been developed using BNT system and SCT system, respectively. Developed duplexer filter was formed to have Tx frequency band at 836.5 (($\pm$12.5)MHz and Rx frequency band at 881.5 ($\pm$12.5)MHz. Insertion loss at Tx frequency band was 1.41dB and 1.46dB, insertion loss at Rx frequency band was 3.49dB and 3.65dB, respectively. Especially, duplexer filters using dielectric cermaics with ${\varepsilon}$r = 180 were 8% smaller than commercially manufactured duplexer filters using dielectric ceramics with ${\varepsilon}$r = 90 by murata.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.4
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• pp.1-10
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• 1993

This paper presents the designing/manufacturing scheme of the diplexer for satellite transponder which is composed of 2-channel bandpass filters, coupled with E-plane T-junction, having symmetrical waveguide E-plane step discontinuity structures. The 2-channel bandpass filters of the diplexer are designed by the scheme of connecting ${\lambda}_{g}$/2 shunt stub to the waveguide E-plane, playing the role of heat sinks without attaching a special heat sinks and to give the profitable productivity and allow the low-cost manufacturing at mass production, tuning screws are eliminated which have been used to compensate the operating characteristics of manufactured filters. The 2 channel bandpass filters of manufactured 14/12 GHz diplexer for domestic Ku-band satellite transponder have the return loss of 25 dB, insertion loss of 0.3 dB in passband, and below-50 dB of stopband characteristics (T$_{x}$ : f$_{o}{\pm}$250 MHz, R$_{x}$ : f$_{o}{\pm}$220 MHz) at room temperature.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.237-239
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• 2003

A high-temperature superconductor (HTS) journal bearing was studied for loss. Two HTS bearings support the rotor at top and bottom. The rotor weight is 4 kg and the length is about 300 mm. Both the top and bottom bearings have two permanent magnet (PM) rings with an iron pole piece separating them. Each HTS journal bearing is composed of six pieces of superconductor blocks of size 35$\times$25$\times$10 mm. The HTS blocks are encased in a cryochamber through which liquid nitrogen flows. The inner spool of the cryochamber is made from G-10 to reduce eddy current loss, and the rest of the cryochamber is stainless steel. The magnetic field from the PM rings ＜ 10 mT on the stainless part. The rotational drag was measured over the same speed range. Results indicate that the 10 mT design criteria for magnetic field on the stainless part of the cryochamber is too high.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1042-1044
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• 2003

High speed PM machines are being developed as motor/generators for gas-turbine generator sets in smaller power sizes, and as motors for number of applications including gas compressors, machine tools and turbo molecular pumps. Due to the high peripheral speed of the rotor and the relatively high conductivity of the magnets used, rotor eddy current loss can be substantial. This paper deals with the calculation of rotor eddy-current losse in permanent magnet(PM) high speed motor using the analysis of harmonics.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1323-1329
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• 2011

The purpose of study was to analyze how the visual information affects balance control of individuals during single leg stance. A total of 27 young normal people (20 males and 7 females, age: $13.7{\pm}2.6$, height: $162.3{\pm}13.2$ cm, weight: $53.9{\pm}13.9$ kg) was voluntarily involved in the experiment. The subjects were requested to maintain balance for 20 seconds with eyes both open and closed on a force plate and then foot ground reaction data were collected for that duration. Results showed that mean velocity of COP in closed eyes condition was larger 1.84 times than that of the open-eyes condition and range of vertical angle was increased approximately one degree in the closed eyes condition. To accomplish a balance, the frequency power in mediolateral and anteroposterior components of the foot-ground reaction force was increased by 1.3~1.4 times. Consequently, visual absence during single leg stance can result in critical loss of balance and lead to instability of body control.

• CELLMED
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• v.5 no.2
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• pp.12.1-12.3
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• 2015

Adolescent menorrhagia is defined as excessive menstrual bleeding from menarche to adolescents. It is a distressing condition both for the patient as well as for her parents. If it is not managed in time itmay pose significant health problems that may leads to blood transfusion. We determined the efficacy of Geru (Red ochre) in controlling the amount and duration of blood flow in patients of Adolescent menorrhagia. This study included 40 teenage girls, who presented with heavy bleeding during menstruation to Outpatient Department, Sameena Maternity Nursing Home, Hyderabad during the year of 2013. Assessment of each case was done by history and Pictorial Blood loss Assessment Chart (PBAC) score. Geru powder was given for 2 cycles and results were assessed. The data was analyzed statistically. The mean PBAC score before treatment was $497.04{\pm}389.92$ and after trial in $1^{st}$ and $2^{nd}$ it was found to be $471.13{\pm}162.18$ and $310.13{\pm}142.15$ respectively. On basis of results it was concluded that single unani drug Geru is enough in controlling bleeding and was found effective by its astringent and styptic properties.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1782-1791
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• 2017

In this paper, an optimal design of hybrid magnetic levitation(Maglev) system using intelligent optimization algorithms is proposed. The proposed maglev system adopts hybrid suspension system with permanent-magnet(PM) and electro magnet(EM) to reduce the suspension power loss and the teaching-learning based optimization(TLBO) that can overcome the drawbacks of conventional intelligent optimization algorithm is used. To obtain the mathematical model of hybrid suspension system, the magnetic equivalent circuit including leakage fluxes are used. Also, design restrictions such as cross section areas of PM and EM, the maximum length of PM, magnetic force are considered to choose the optimal parameters by intelligent optimization algorithm. To meet desired suspension power and lower power loss, the multi object function is proposed. To verify the proposed object function and intelligent optimization algorithms, we analyze the performance using the mean value and standard error of 10 simulation results. The simulation results show that the proposed method is more effective than conventional optimization methods.

• The Journal of Internal Korean Medicine
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• v.22 no.4
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• pp.683-689
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• 2001

In order to study the anti-stress effect of hyangbujapalmultang, several measures of stress, including body weight changes, organ weight changes and catecholamine changes. The following result have been obtained: 1. The weight loss of contol group was $28.5{\pm}1.8g$, that of sample group was $20.3{\pm}1.6g$. This differance was statistcally significant. 2.The organ weight(Liver,Spleen,Kidney,Adrenal gland) was the only significant change in the spleen, in sample group comparing to control group. 3. The norepinephrine contents of control group was $695.5{\pm}22.7pg/ml$, that of sample group was $607.4{\pm}21.7pg/ml$. This shows significant difference in sample group comparing to contol group. 4. The epinephrine contents of control group was $212.8{\pm}9.8pg/ml$, that of sample group was $182.6{\pm}8.4pg/ml$. This shows significant differance in sample group comparing to control group. 5. The dopamine contents of control group was $504.5{\pm}31.3$, that of sample group was $463.4{\pm}27.8pg/ml$. This shows the value decreased, but none of it is significant. Based on avove results, it may be conculed that hyangbujapalmultang has anti-stress effects.

• Journal of Trauma and Injury
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• v.28 no.1
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• pp.15-20
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• 2015

Purpose: Vascular injuries caused by traffic, industrial accidents and by outside activities have increased in Korea. Especially, vascular injuries to the extremities can lead to limb loss and even mortality if they are not appropriately treated. The aim of the study was to evaluate the surgical outcomes of femoropopliteal vascular management after trauma. Methods: The medical records of 12 patients with femoropopliteal vascular injuries who were treated at Dankook University Hospital from 2011 to 2013 were reviewed. Iatrogenic vascular injuries were excluded. The clinical data including the causes of injury, associated injuries and surgical outcomes were analyzed retrospectively. Results: All patients were male, with a mean age of $46.8{\pm}16.3years$ (range: 26~69 years). The causes of vascular injuries were four traffic accidents, three industrial accidents, two iron plates, one outside activity, one glass injury and one knife injury. The average transit time between the place of the accident place and the emergency department was $3.0{\pm}2.1$ (0.5~12.5) hours, and the average preparation time for surgery was $8.0{\pm}6.7$ (1.7~23.3) hours. The anatomic injuries included the popliteal vessel in seven cases and the femoral vessel in five cases. The average Injury Severity Score (ISS) was $12.0{\pm}5.0$ (5~17), and the average Mangled Extremity Severity Score (MESS) was $5.7{\pm}2.1$ (2~9). The operation methods were four interposition grafts, three end-to-end anastomoses, two direct repairs and three patch angioplasties. One case required amputation of the injured extremity. Conclusion: Early recognition and revascularization of the injured vessel are mandatory to reduce limb loss and to obtain satisfactory outcomes. Therefore, careful/rapid evaluation of the vascular injuries and timely/successful surgical treatment are the keys to salvaging an injured limb.

• The Journal of Advanced Prosthodontics
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• v.11 no.3
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• pp.162-168
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• 2019

PURPOSE. The aim of this study was to evaluate the effect of occlusal adjustments on the surface roughness of yttria-tetragonal zirconia polycrystal (Y-TZP) and wear of opposing artificial enamel. MATERIALS AND METHODS. Twenty-five Y-TZP slabs from each brand (Lava, 3M and Bruxzir, Glidewell Laboratories) with different surface conditions (Control polished - CPZ; Polished/ground - GRZ; Polished/ground/repolished - RPZ; Glazed - GZ; Porcelain-veneered - PVZ; n=5) were abraded (500,000 cycles, 80 N) against artificial enamel (6 mm diameter steatite). Y-TZP roughness (in ${\mu}m$) before and after chewing simulation (CS) and antagonist steatite volume loss (in $mm^3$) were evaluated using a contact surface profilometer. Y-TZP roughness was analyzed by three-way analysis of variance (ANOVA) and steatite wear by two-way ANOVA and Tukey Honest Difference (HSD) (P=.05). RESULTS. There was no effect of Y-TZP brand on surface roughness (P=.216) and steatite loss (P=.064). A significant interaction effect (P<.001) between surface condition and CS on Y-TZP roughness was observed. GZ specimens showed higher roughness after CS (before CS - $3.7{\pm}1.8{\mu}m$; after CS - $13.54{\pm}3.11{\mu}m$), with partial removal of the glaze layer. Indenters abraded against CPZ ($0.09{\pm}0.03mm^3$) were worn more than those abraded against PVZ ($0.02{\pm}0.01mm^3$) and GZ ($0.02{\pm}0.01mm^3$). Higher wear caused by direct abrasion against zirconia was confirmed by SEM. CONCLUSION. Polishing with an intraoral polishing system did not reduce the roughness of zirconia. Wear of the opposing artificial enamel was affected by the material on the surface rather than the finishing technique applied, indicating that polished zirconia is more deleterious to artificial enamel than are glazed and porcelain-veneered restorations.